Ask HN: What are the most useful Chrome extensions?

In other words, what are your favorite Chrome extensions and why?

My top 3 most used Chrome extensions to help with productivity and stay focused while coding.

Tabs Outliner | https://chrome.google.com/webstore/detail/tabs-outliner/eggkanocgddhmamlbiijnphhppkpkmkl

Papaly - Bookmarker | https://chrome.google.com/webstore/detail/new-tab-bookmark-speed-di/pdcohkhhjbifkmpakaiopnllnddofbbn

Limitless - Productivity Manager | https://chrome.google.com/webstore/detail/be-limitless/jdpnljppdhjpafeaokemhcggofohekbp